Remote reading magnetic compasses are known for providing an electrical output signal representative of compass heading. A particularly effective remote reading compass is the subject of U.S. Pat. No. 3,833,901 assigned to the assignee of this invention in which a compass disk is coded by a plurality of selectively light transmissive and opaque optical tracks which are electro-optically sensed to provide an output indication of compass heading in the form of a plurality of digital output signals which can be conveyed to a suitable display for providing a numerical or other visual representation of heading. Such compasses are typically employed on ships or marine buoys in which usual sea level pressures are encountered. Such remote reading compasses are, however, also useful in submerged or other high pressure environments and thus the compass housing must be capable of withstanding the often enormous pressure of the working depth. In order to withstand a high external pressure, the compass housing must be of a material of sufficient strength to retain its integrity in the presence of such high pressure. In general, a high pressure compass housing would be of a construction different than that employed for surface operation where high operating external pressures are not encountered.